At least on Arch Linux, if when trying to launch Keepass you get:
$ keepass
* Assertion at aot-runtime.c:2638, condition `is_ok (error)' not met, function:decode_cached_class_info, Image out of date
=================================================================
Native Crash Reporting
=================================================================
Got a SIGABRT while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.
=================================================================
=================================================================
Native stacktrace:
=================================================================
0x55769f3f4f19 - mono :
0x55769f39e437 - mono :
0x55769f3ecd6c - mono :
0x7f876803e710 - /usr/lib/libc.so.6 :
0x7f876808e83c - /usr/lib/libc.so.6 :
...
Most likely your system recently updated Mono. You’ll need to reinstall Keepass to fix it:
$ pacman -S keepass